'use strict'

const path = require('path')
const fs   = require('fs')
const url  = require('url')

// Make sure any symlinks in the project folder are resolved:
// https://github.com/facebookincubator/create-react-app/issues/637
const appDirectory = fs.realpathSync(process.cwd())
const resolveApp   = relativePath => path.resolve(appDirectory, relativePath)

const envPublicUrl = process.env.PUBLIC_URL

function ensureSlash(path, needsSlash) {
	const hasSlash = path.endsWith('/')
	if (hasSlash && !needsSlash) {
		return path.substr(path, path.length - 1)
	}
	if (!hasSlash && needsSlash) {
		return `${path}/`
	}
	return path
}

const getPublicUrl = appPackageJson => envPublicUrl || require(appPackageJson).homepage

// We use `PUBLIC_URL` environment variable or "homepage" field to infer
// "public path" at which the app is served.
// Webpack needs to know it to put the right <script> hrefs into HTML even in
// single-page apps that may serve index.html for nested URLs like /todos/42.
// We can't use a relative path in HTML because we don't want to load something
// like /todos/42/static/js/bundle.7289d.js. We have to know the root.
function getServedPath(appPackageJson) {
	const publicUrl = getPublicUrl(appPackageJson)
	const servedUrl = envPublicUrl ||
    (publicUrl ? url.parse(publicUrl).pathname : '/')
	return ensureSlash(servedUrl, true)
}

// config after eject: we're in ./config/
module.exports = {
	dotenv         : resolveApp('.env'),
	appBuild       : resolveApp('build'),
	appPublic      : resolveApp('public'),
	appHtml        : resolveApp('public/index.html'),
	appIndexJs     : resolveApp('src/index.web.js'),
	appPackageJson : resolveApp('package.json'),
	appSrc         : resolveApp('src'),
	yarnLockFile   : resolveApp('yarn.lock'),
	testsSetup     : resolveApp('src/setupTests.js'),
	appNodeModules : resolveApp('node_modules'),
	publicUrl      : getPublicUrl(resolveApp('package.json')),
	servedPath     : getServedPath(resolveApp('package.json')),
}
